The role for this core is to support all the projects in their requirements for single nucleotide polymorphism (SNP)1 analysis, gene mapping and sequencing. Support will be provided by several means with emphasis placed on: 1) High volume scoring of SNP and microsatellite polymorphisms in humans and mice; and 2) the processing and analysis of dideoxy-terminated sequencing reactions produced by the individual projects. In addition, the core will aid the projects in the preparation of genotype and sequence data in formats most useful for further analysis. Human mapping data will be formatted for forwarding to the Bioslatistics Core.